You will definitely want to start reading labels on all processed food. Most processed food is loaded with sodium (and depending upon what the food is, fat and sugar too.)
A healthy diet should have somewhere between 1200 and 1800 mgs of sodium per day. The average American diet has 10 to 20 times that much! So one of the first things to do is start looking at the nutrition information on the packages (cans, bottles, boxes, pouches etc.) The sodium is listed per serving (not for the entire contents of the package). So you have to figure out how much a serving is (which will be listed also).
A lot of people just start eating without any regard to the per serving size. So if you start out with a per serving size of 1 teaspoon of mustard, for example, which may have 90 mgs of sodium, if you double or triple or quadruple that 1 teaspoon serving size, you will be multiplying the amount of sodium! Also, you need to use real measuring spoons and cups to be sure you are only getting the true amount of the serving size. Your regular spoons that you eat cereal with are probably not true “teaspoons” or “tablespoons.”
So whenever you eat a processed food, you need to be aware of the serving size and then start getting used to adding up the amount of sodium (and other contents like sugar and fat) and trying to keep the amount within the healthy range. So if you eat a sandwich, you have to account for the entire amount of sodium that is in the bread, the mustard, the mayonaise, the cheese, the pickles etc. and add up those amounts. If you use more than the serving size, you have to keep adding more miligrams to your daily total.
I’ve found it helpful to try to find foods that have a low sodium content (per serving) in the first place. So that would be around 140 mgs. And look for products that say low sodium on the label (or no salt added). But you still have to check the actual per serving size.
It is much more difficult to control your intake of sodium, fat and sugar when you eat at a restaurant, but most restaurants now offer a nutrition list if you ask for it. You will be shocked at how much of these items are in all processed and restaurant foods, but when you start reading labels on a regular basis, you will get to know which foods are better than others.
You should aim to eat a more plant based diet. Eat fruits and vegetables with every meal. Add un-salted nuts (if you are not allergic to them) daily. Like some of the others have said, limit your meat consumption. Meat should only be a small side portion and not the main dish. If you can, try eating meat-less meals once a week and then add more meat-less days to your week once you get used to not eating meat.
As a teenager, you need to make sure that you get enough calcium, but get it through low and non-fat dairy products instead of full fat dairy products. Good sources are low or non-fat milk, cheese, yogurt. Many other non-dairy foods contain calcium such as dark green leafy vegetables and tofu. Here is an article all about calcium (where to find it and how much you need) here
You want to drink water and plain (unsweetened) brewed black and green teas (preferably without caffeine) which are loaded with healthy anti-oxidants (which are good to keep your cells intact and functioning properly) and occasionally you can drink some juices like orange and cranberry, but you don’t want to drink them everyday because they do have a lot of sugar. Only drink 100% juice (which it will clearly say on the label). Some drinks appear to be “juice” but they are really nothing more than sugar water with a juice flavor added. Low or non-fat milk and yogurt drinks are good too. Stay away from soda and Kool-aid and other sugary drinks.
It might be a good idea to learn to cook too. Learning to cook really changed my ideas about what things to eat and where food comes from and how different cooking methods can be much more healthy than other methods.
If your family currently eats butter or regular margarine, you might want to switch to one of the new “healthier” style margarines, that contain no cholesterol or trans fats (2 other ingredients to watch out for in foods) The one that I use is called Smart Balance and I think it tastes great.
Sometimes, when you start adding new foods into your diet, you may have to taste them 2 to 10 times before you acquire a taste for them. So if you don’t like something right away, keep tasting it (maybe with a different method of preparation) and then hopefully you will end up adding a whole bunch of new foods to your diet. I used to hate mushrooms and Brussels sprouts, but I kept trying them out and now I love them.
You will also want to make sure you are getting enough fiber in your diet. Most Americans don’t get anywhere near the recommended 20 to 35 grams per day. Adding fruits and vegetables and whole grains into your diet will help with this. When you get a little older (like into your 30’s and 40’s) or if you already have some problems with constipation, you also might want to add a fiber supplement like Bob’s Red Mill Ground Flax Meal (2 tablespoons daily, keep refrigerated) or Trader Joe’s Psyllium Husk (1 heaping teaspoon daily, keep in a cool dry place) or Metamucil Just make sure you drink lots of water when you take these supplements.
Try different methods of cooking (or preparations at restaurant) so instead of having deep fried chicken, make your chicken grilled. Instead of having a breading on the outside of your chicken, have it without breading and without the skin. Eat a baked potato with non-fat plain yogurt and some chopped green onions, or salsa instead of eating French fries. Have a turkey sandwich (with lettuce and tomato, hold the mayo and cheese) instead of a cheeseburger. When you order a salad or anything with a dressing or sauce, get it on the side so you can limit the amount. Switch to oil and vinegar dressings instead of cheese and mayo and sour cream based dressings. Learn to use marinades, herbs and spices and pepper and salsas and vinegars and fruit juices to give flavor to foods instead of using salt and butter and mayonaise.
If you’re not already eating these foods, here are some nutritional powerhouses to add: tofu, sweet potatoes, kale and other leafy greans, broccoli, cauliflower, cabbage, lettuces (except iceberg which has almost no nutrients and not much fiber) carrots, beets, Brussels sprouts, rutabagas, turnips, radishes, mushrooms, un-salted nuts, peppers (from sweet to hot) beans (of all kinds), whole grains (whole wheat bread, quinoa, bulgur, brown rice, oatmeal, un-salted popcorn, barley, wheat berries, cornmeal) tomatoes, apples, pears, berries (of all kinds including cranberries) oranges, pineapple, mangoes, cherries (especially dried) and avocados. And take a multi-vitamin for your age and sex. PM me if you want any recipes. :- )